Abstract: A medical implant includes a first implant body and a pre-coating covering at least a portion of an outer surface of the first implant body. The pre-coating has a negative Poisson's ratio. A method of making a medical implant includes applying a precursor material on a surface of a first implant body, the first implant body having a positive Poisson's ratio.

Abstract: A ski includes an elongated ski body having a bottom layer defining a bottom surface of the ski, a top layer defining a top surface of the ski, and a middle layer disposed between the bottom layer and the top layer, in which the middle layer includes a negative Poisson's ratio (NPR) foam material having a Poisson's ratio of between 0 and ?1.

Abstract: A door includes a rectangular panel having a first face, a second face, and two pairs of opposing edges, in which the edges of each pair of edges are parallel and in which a first pair of edges is longer than a second pair of edges. The rectangular panel includes a layered composite material, in which a first layer of the composite material has a positive Poisson's ratio (PPR) and a second layer of the composite material is disposed in contact with the first layer and that includes a material having a negative Poisson's ratio (NPR). The door includes a hinge including plates joined together by a joint, in which a first one of the plates is attached to a first one of the edges of the first pair of edges and in which a second one of the plates extends beyond the first one of the edges. The door also includes a handle opening defined through a thickness of the rectangular panel.

Abstract: The disclosure describes a zipper including two rows of zipper teeth, in which at least some of the zipper teeth include a negative Poisson's ratio (NPR) foam material having a Poisson's ratio of between 0 and ?1, and a slider movably attached to one of the rows of the zipper teeth and configured to connect the two rows of zipper teeth when the slider is moved in a first direction and to disconnect the two rows of zipper teeth when the slider is moved in an opposite direction.

Abstract: A circuit chip includes a first body having a negative Poisson's ratio; a second body having a positive Poisson's ratio, wherein the first body and the second body are stacked on one another and thermally coupled to one another; and a first integrated circuit embedded in the second body.

Abstract: An intraocular lens includes a substantially circular lens element formed of a transparent material and one or more haptics extending outwardly from an outer edge of the lens element. The one or more haptics are formed of a polymer foam material having a negative Poisson's ratio (NPR) and are configured to couple the intraocular lens to an eye of a patient. The lens includes an inner region having a first index of refraction and an outer region disposed circumferentially surrounding the inner region, the outer region having a second index of refraction different from the first index of refraction.

Abstract: In an aspect, a sports ball includes a core including a negative Poisson's ratio (NPR) foam material, in which the core has a Poisson's ratio of between 0 and ?1, and in which the NPR foam material includes an NPR polymer foam; and a cover layer surrounding the core. In an aspect, a golf club includes an elongated shaft; a grip disposed at a first end of the elongated shaft; and a head connected to a second end of the elongated shaft, the head having a flat face configured for contact with a golf ball, in which the flat face is formed of a negative Poisson's ratio (NPR) foam material, in which the head has a Poisson's ratio of between 0 and ?1, and in which the NPR foam material includes an NPR metal foam, an NPR ceramic foam, or an NPR-PPR composite foam.

Abstract: Corrugated paper includes first and second sheets of paper; and a layer of structured paper disposed between the first and second sheets of paper. The layer of structured paper includes cells, in which at least some of the cells are negative Poisson's ratio (NPR) cells. Each NPR cell includes top and bottom walls, and side walls angled inwards toward a central portion of the NPR cell, such that application of a compressive force between the top and bottom walls of the NPR cell causes a lateral dimension of the NPR cell between opposite side walls to decrease. The NPR cells exhibit a Poisson's ratio of between 0 and ?1.

Abstract: A brick includes outer walls defining a hollow interior space, the outer walls including: substantially flat top and bottom walls; and side walls angled inwards toward a central portion of the NPR brick, such that application of a compressive force between the top and bottom walls causes a lateral dimension of the brick between opposite side walls to decrease. At least some of the outer walls of the brick include a material having a negative Poisson's ratio (NPR).

Abstract: A medical implant includes a first implant body and a pre-coating covering at least a portion of an outer surface of the first implant body. The pre-coating has a negative Poisson's ratio. A method of making a medical implant includes applying a precursor material on a surface of a first implant body, the first implant body having a positive Poisson's ratio.

Abstract: A ski includes an elongated ski body having a bottom layer defining a bottom surface of the ski, a top layer defining a top surface of the ski, and a middle layer disposed between the bottom layer and the top layer, in which the middle layer includes a negative Poisson's ratio (NPR) foam material having a Poisson's ratio of between 0 and ?1.

Abstract: An assembly includes an elongated, cylindrical pipe; a plumbing connector attached to an end of the pipe, in which an opening is defined through a length of the plumbing connector; and a negative Poisson's ratio (NPR) coating disposed on an interior surface of the plumbing connector that defines the opening, in which the NPR coating on the plumbing connector is configured to exhibit an auxetic behavior in response to application of a force to the NPR coating, in which the end of the pipe is disposed concentrically within the opening of the plumbing connector such that the NPR coating of the plumbing connector contacts an outer surface of the pipe, and in which a portion of the plumbing connector extends beyond the end of the pipe.

Abstract: A door includes a rectangular panel having a first face, a second face, and two pairs of opposing edges, in which the edges of each pair of edges are parallel and in which a first pair of edges is longer than a second pair of edges. The rectangular panel includes a layered composite material, in which a first layer of the composite material has a positive Poisson's ratio (PPR) and a second layer of the composite material is disposed in contact with the first layer and that includes a material having a negative Poisson's ratio (NPR). The door includes a hinge including plates joined together by a joint, in which a first one of the plates is attached to a first one of the edges of the first pair of edges and in which a second one of the plates extends beyond the first one of the edges. The door also includes a handle opening defined through a thickness of the rectangular panel.

Abstract: A cooking vessel includes a base having a flat bottom and a sidewall connected to and surrounding the base, thereby defining an interior space configured for containing food. The base comprises a layered composite material that includes a first layer of the composite material has a positive Poisson's ratio (PPR) and a second layer of the composite material is disposed in contact with the first layer. The cooking vessel includes a material having a negative Poisson's ratio (NPR).

Abstract: The disclosure describes a zipper including two rows of zipper teeth, in which at least some of the zipper teeth include a negative Poisson's ratio (NPR) foam material having a Poisson's ratio of between 0 and ?1, and a slider movably attached to one of the rows of the zipper teeth and configured to connect the two rows of zipper teeth when the slider is moved in a first direction and to disconnect the two rows of zipper teeth when the slider is moved in an opposite direction.

Abstract: A gas storage apparatus includes a foam body having a negative Poisson's ratio, and a gas impregnated in closed cells of the foam body, the gas having a pressure above atmospheric pressure. A method of making a gas storage apparatus includes providing a first body comprising a precursor material, and, while the first body is in an atmosphere including a gas, applying a stimulus to the precursor material, the stimulus causing the precursor material to form a closed-cell porous foam structure having a negative Poisson's ratio. Cells of the closed-cell porous foam structure encapsulate the gas at a pressure above atmospheric pressure.

Abstract: Corrugated paper includes first and second sheets of paper; and a layer of structured paper disposed between the first and second sheets of paper. The layer of structured paper includes cells, in which at least some of the cells are negative Poisson's ratio (NPR) cells. Each NPR cell includes top and bottom walls, and side walls angled inwards toward a central portion of the NPR cell, such that application of a compressive force between the top and bottom walls of the NPR cell causes a lateral dimension of the NPR cell between opposite side walls to decrease. The NPR cells exhibit a Poisson's ratio of between 0 and ?1.

Abstract: An impact protection device includes a cushion formed from a first material having a negative Poisson's ratio (NPR) and a second material having a positive Poisson's ratio (PPR). The first material and the second material can be layered or can be formed as a matrix of cells. The impact protection device can be an airbag with the cushion coupled to an inflation source or an expulsion source for deploying the airbag in response to an impact. The impact protection device can also be an impact vest with the cushions positioned on the vest body for absorbing impact forces to the vest body. The combination of the NPR and PPR materials improve the impact absorption of the impact protection devices compared to conventional materials.

Abstract: An intraocular lens includes a substantially circular lens element formed of a transparent material and one or more haptics extending outwardly from an outer edge of the lens element. The one or more haptics are formed of a polymer foam material having a negative Poisson's ratio (NPR) and are configured to couple the intraocular lens to an eye of a patient. The lens includes an inner region having a first index of refraction and an outer region disposed circumferentially surrounding the inner region, the outer region having a second index of refraction different from the first index of refraction.

Abstract: An artificial heart valve includes a frame, one or more struts attached to the frame, and a leaflet configured to open and close a fluid flow path through the frame by moving in response to heartbeats. Movement of the leaflet is restricted by the one or more struts. The leaflet includes an inner leaflet body having a negative Poisson's ratio, and an outer leaflet body at least partially surrounding the inner leaflet body, the outer leaflet body having a positive Poisson's ratio.